The events of September 11 dealt a terrible blow to our self-perception as western liberals. We always suspected that we, the postwar generations, were peculiarly privileged but also soft and untested.

Now we have witnessed an act of terror which has quite literally first terrified and then pulverised 6,000 people in front of our eyes. This experience has dealt a grave psychological blow to our liberal belief system.

We've tended to believe that conflict and difference can ultimately be resolved by talking, by rationality, by negotiating, by treating all sides decently and fairly. Even if, as has been the case with America's realpolitik, these rules are not observed, we still expect countries to try to play by them. But the attack on the World Trade Centre bypassed all that. It belonged to a different system altogether, where all previous models of resolving conflict were brushed aside.

We've never seen the rules of human behaviour broken at this pitch before. One result has been a tangible increase in anxiety, with Londoners worrying about the risk of travel, the risk of going into crowded places or near areas which could be construed as "symbolic targets". I've even heard of one person stocking up on bottled water for fear of poison in the water supply. Along with this anxiety comes anger. Not the self-righteous, retributive anger of military retaliation, but something more unsettling.

Of course I'm angry that all those fair minded well intentioned liberal beliefs have been abused. But I'm also angry at liberalism's wilful self-delusion that humanity is essentially good. Looking back, it seems we never truly assimilated what the Holocaust meant. With Bosnia and Rwanda, we didn't look at the issue of what humanity was capable of, only what had caused the events in these circumstances. We always blame fascist regimes. But fascist regimes are human regimes.

We seem to have left ourselves at risk by denying the shadow and darkness which Martin Amis in this paper described as species shame. This is not a question of evil versus good, but of a collective sense of what we as a species are capable of doing.

We are equally deluded in our notion that humanity is inexorably advancing from primitive violence towards democratic tolerance. The people who committed these atrocities are not primitives from backward cultures, whatever Bush might say. Many have grown up alongside and within advanced capitalist societies, as is clear from the extraordinary pictures of Bin Laden and his family beside a pink Cadillac in 70s Sweden. Their acts have come from a violent repudiation of that culture, and the awful embrace of infantile cults of revenge.

Somehow our collective failure to interrogate what has been brewing in fundamentalism marks another failure of liberalism. It now seems utterly naive that delicacy about "other faiths" meant we weren't able to recognise fascistic tendencies.

Feminists tried, picking up early on the Taliban's atrocities and compared them to Nazism. It is women who have been hostile to kow-towing to religious fundamentalism, whether Christian, Jewish or Muslim. Women recognised that systems which entail using female bodies for reproductive, territorial or moral statements are not easy allies. But a liberal squeamishness did not want to know.

These are serious blows to our sense of who we are, what we expect of the world and of our interactions with others. They require mental shifts, perhaps an awakening. For Americans, that awakening might be from their isolation and political insularity. For European democracies, an awakening from their naivety; producing confidence in what our core social values are and what we need to do to safeguard them.

This is clearly a critical moment. We need politicians and leaders who can inspire us with confidence. Yet none of our leaders is doing this. Instead naivety still seems to rule. Bush and Blair are asking us to fight a war against terror. But, as any fool should know, if we do, terror will strike back. Not as one army lined up against another, but as terror fights - with stealth, unexpectedly, without warning, without claims of responsibility. It will bypass the military and sacrifice the lives of ordinary people.

When rules are broken at such a pitch, the need to retaliate is understandable. But a military response on an ill-defined target is woefully dangerous. Behind this need to retaliate is the damage to our world view. And what is needed now is charismatic leaders who can assimilate the new thinking that results from this awful awakening. We want figures who embody our feelings, represent a wise assimilation and a thoughtful new political response. But as we do not seem to have such leaders, our anxiety is acute.

By the cruellest of fates, the fanatics have no such problem. The contrast between their leadership and ours is embodied in the difference between Bush and Bin Laden. Bin Laden does not even have to speak. His icon so potently embodies his cause. The irony is that if children were asked to draw Christ, they would drawn Bin Laden - not just because of how he dresses, but for his whole demeanour. His is the look of Christ-like suffering, with all the intense sexual ambiguity that goes with it. He looks like someone who has suffered an earlier psychological wound. That look matches the fanatic's ideology; he looks like a victim, languidly feminine, but with his gun over his shoulder he viciously repudiates this femininity and embraces machismo.

Against this we have Bush: dazed and confused, grasping at thoughts that refuse to form into meaningful words. This at a time when we need leadership to acknowledge our species shame and how to live with it.